Putty powder and putty compositions made therefrom



May 24,1960 B. B. MCHAN 2,937,954

PUTTY POWDER AND PUTTY COMPOSITIONS MADE THEREFROM I Original FiledApril 3. 1956 2 Sheets-Sheet 2 u 2 2 W MES & 7'I 'I a? S: 1 2 Nbu; s waa w INVENTOR. B/QCE/Y HQZZ, E25 BY MW- United States Patent .PUTTYPOWDER AND PUITY COMPOSITIONS MADE THEREFROM Original application Apr.3, 1956, Ser. No. 575,861. Di-

vided and this application Mar. 13, 1957, Ser. No.

4 Claims. (Cl. 106-260) The present invention relates to improved putty,caulking and glazing compounds and other putty-like products exhibitinghighly desirable properties including a high degree of plasticity,better Working qualities, improved wearing qualities, improved keepingqualities and less oil requirements. More specifically, the presentinvention is directed to new and improved pulverized limestone powdershaving improved physical properties from which putty and putty-likeproducts having the aforementioned imp'roved properties can bemanufactured.

Putties, caulking and glazing compounds must have certain definitephysical characteristics in order to meet the requirements ofapplication to the glass, wood and metal sash. They must be of suchconsistency that they .-can be easily and properly applied by theglazier, either by hand or by gun. In order to meet these requirementsthey must have the proper body consistency, plastic flow and adhesion.The desirable properties can be partially developed by the oil andvehicles used to produce the putty. However, to produce putties, caulking and glazing compounds having the desirable and necessary propertiesthe powder, which usually constitutes approximately 75% to 85% by weightof the finished product, must also have the inherent property ofdeveloping the required degree of plastic flow and cohesion andadhesion. The powder must, also, develope these required physicalproperties with a wide range of oils and other vehicles commonly used informulating products in this category.

Putty powders are commonly made from three sources of stone. In the pastthe most general source of putty powders was English chalk or otherimported chalk whitin'g. Many putties were produced by the use ofnothing more than linseed oil and imported whiting. Later this practicewas changed and highly modified by the use of crystalline groundlimestones in which was incorporated from 20% to 40% of chalk whiting.The use of a pure chalk whiting powder produced a putty having a veryhigh oil absorption which was extremely long and sticky, difficult toapply and did not give satisfactory wearing performance on the sash. Theuse of a modified product consisting of a portion of crystalline groundlimestone along with a moderate percentage of English chalk producedpowders of a suflicient degree of plasticity and adhesion that were muchmore easily applied tothe sash, in many cases with actually superiorWearing and performance qualities. Also, less oil was required by thecombined chalk and limestone powder.

The use of chalk has largely been abandoned in the last few years andhas been replaced in the United States particularly by powders producedfrom selected limestones. The production of suitable powdersfromlimestones requires grinding and sizing under rigid control.

2. Ground limestone powders are now produced in a wide range of particlesize distribution to meet the requirements of the various grades andclassesof putties, caulking and glazing compounds.

Limestones suitable for the production of putty powders are found inthree varieties, i.e., crystalline, cryptocrystalline and oolitic.Marble is also used for this purpose and is classified mineralogicallywith the crystalline limestones. The morphological characteristics ofthe crystalline limestones are greatly varied. Dana, E. S., in hisSystem of Mineralogy, illustrates 39 forms of the calcite crystal. Inthis same book oolitic limestone is defined as a granular limestone butits grains are minute rounded concretions, looking somewhat like the roeof fish. The concretionary grains will range in size from minute, almostmicroscopic sized spheroids to pieces as large as apea.

The oolitic stone giving the most satisfactory powders for use in putty,caulking and glazing compounds is made from those containing relativelysmall round concretionary structures that are macroscopic in size andcan just be well seen with the unaided eye. This type of limestone, whenproperly ground, produces a putty having the required degree of plasticflow. With pure raw linseed oil they produce putties that have a longtenacious string and high degree of adhesion and extraordinarily goodworking properties and wearing quality. Unfortunately, the extent ofoolitic deposits suitable for the production of putty powders isseverely limited. Only a few deposits have been discovered and atpresentonly one is being Worked for this purpose in the United States.

There are many deposits of crystalline limestone of .a highdegree ofpurity and having satisfactory color or whiteness from which suitableputty powders could be produced if the proper degree of plastic flow andother desirable properties could be developed in these powders.

Powders produced from crystalline stones are usually characterized by ashort and mealy type of plastic flow and a lack of adhesion and internalcohesion. They are inclined to be mealy and work very poorly whenapplied in putty form to the sash by the glazier. Such putties often donot have the required degree of suspension and are inclined to settlebadly in the container during storage, much of the oil separating andrising to the top and the powder settling to a hard cake in the bottom.

Putties, caulking and glazing compounds must meet the demands ofservice. Caulking compounds must remain soft and plastic with perfectadherence to the building material, be it eithersteel, brick, stone, orconcrete. After being applied, the oil must not separate and stain thebuilding. These compounds must stand up in actual service for areasonable period without deterioration from weathering influence. Theymust not chip, crack, or peel permit-ting the entry of water into thewood or steel sash or around the crevices in the building structure.

One of the commonly used methods for developing the required degree ofplastic flow and plasticity from crystalline powders depends on the useof a moderately large percentage of heavy bodied blown or heavy kettlebodied drying oils. These generally have a viscosity of Z-2 to Z6, onthe order of from 36.2 to 148 poises, and are quite expensive incomparison with the straight raw oils or clarified oils. Most puttyformulas today that are based on crystalline powders are made with thevehicle portion containing anywhere from 20% to 40% of one of thespecially treated heavy bodied oils in rder to assmsa develope therequired degree of plastic flow and suspension quality. Typical formulasare:

VEHICLE PORTION Polymerized oil, linseed or soya, heat bodied,

or blown: Percent Viscosity Z-4 71.0 Mineral seal oil 12.5 Oleum spiritsu 12.5 Fatty acids of linseed oil 2.0 Dryer 2.0

Polymerized oil, linseed or soya, heat bodied,

or blown:

Viscosity Z-4 30-60 Raw oil, clarified or degummed, linseed or soya56-26 Mineral seal oil 5.0 Oleum spirits 5.0 Fatty acids of linseed oil2.0 Dryer 2.0 These are quite expensive oil formulas. In the very wideapplication of huge quantities of these products, additional items ofexpense constitute a serious consideration. The extra expense incurredin the use of the special oils very often prevents the development,application and use of desirable products, where in many cases it wouldbe a real contribution to certain phases of present day'industrial arts.

The heavy bodied oils in the vehicle formulas have the very peculiarproperty of being preferentially adsorbed over the surface of thecalcium carbonate particles. In this condition they exert a verypeculiar type of surface attraction that causes the particles toaggregate in definite types of aggregated structure in the form of long,rod-type aggregates, which gradually bend and become circular in form.These can be easily seen on microscopic examination. This type ofstructure of the aggregated powder particles, due to the adsorption ofthe heavy bodied oil, lends to the putty the property of long plasticityand the required degree of adhesion and cohesion. Due to the developmentof these properties, the resultant product, also, has extraordinarilygood suspension. That is, the structure causes the oil to be retained inthe interstices and voids around this structure forming an integral webthroughout the contents of a container. This structure is, also, ofgreat importance in its industrial usage. Such putties do not leak orooze oil after being applied on the sash or other building surface onwhich they are used. After being applied they immediately set to a 'veryrigid type of structure which remains in this condition through manyyears of service.

Keeping qualities of the putty in the original package is of greatimportance. Putty often stands in the original container for severalmonths before use. If the product does not have good keeping quality itwill separate and settle to a hard mass at the bottom of the containerwith most of the oil on top. Often the solids at the bottom will hardento a consistency that is impossible to remove by hand and, as aconsequence, reworking on the job becomes impossible.

Plastic flow is defined as the flow in which the rate of shear isproportional to the shearing stress in excess of yield value. This typeof flow of plastic putties may vary from a mealy granular condition thatdoes not possess any apparent flow or string to a putty mass ofextremely'long, smooth, easy plastic flow. All gradations of plasticflow are possible between these extremes. There are certain types ofplastic flow that may do defined roughly and practically as follows:v

Mealy generally means a putty without very much string or flow. Whenpulled it breaks into a short mealy mass and does not hold together. Ithas a very low internal cohesion. Short describes the plastic flow thatbreaks before it can be pulled to any considerable length. When mixedand pulled in the hands it breaks with a short brittle mealy fracture onfolding. This type of flow is usually slightly better than the mealycondition. Long describes the flow of a putty that can be easily pulledinto a long string before breaking. Such putties can be pulled in thehands and bent over and over without breaking. There are, also, certaindefinite types of plastic flow, such as buttery which means abuttery-like consistencywith a short plastic flow, pinching out to ashort buttery fracture. Thixotropic means a putty that sets up to auniform, often stifi, nonplastic body. This consistency will usuallybreak on Working and the original plasticity is restored. Thixotropiccharacteristics may vary from a very short hard cement-like set to athin buttery jelly-like set. v

In order that putties may possess the proper working characteristics inapplication and service, the plastic flow will usually fall in thesemi-short to the semi-long range. Putties must also have enoughinternal cohesion to be pulled readily with the hands and bent over andover without breaking. Such physical characteristics are necessary forproper working by the glazier and determine, to a large degree, the easeof the mechanical application to the sash, be it either metal or wood. 1

In order for putties and caulking compounds to possess the properworking and service characteristics, it is necessary that they have theproper degree of adhesion. By adhesion is meant the tendency or power ofputty to adhere to the surface with which it comes in contact. Theadhesion must be low enough that it can be easily handled and applied bythe glazier, i.e., without sticking to the hands so badily that itcannot be easily worked. The adhesion must also be high enough that itgives firm adherence of the putty mass to the wood and glass and as itdries forming a perfect union and, water-tight bond between putty andthe wood, glass or metal as the case may be.

A putty may have a very high degree of adhesion and yet have such a lowplastic flow that it is impossible to use it. It may, also, have anextremely high plastic flow and such a low adhesion that it does notform a good bond between the wood and glass.

' Suspension in the can, as explained above, is an importantcharacteristic from the standpoint of keeping quality; particularly withthose putties that may be retained on the dealers shelves overcomparatively long periods of time before they are used. The conditionof the putty in the can after standing may vary througha wide range ofconditions, dependent upon the type of powder and vehicle from which itwas made. 'A perfect keeping putty is one which is just as soft afterstanding several months as it was when it was put in the can.

When removed it is uniformly soft from the top to the bottom of thecontainer and of nearly the same consistency as when placed in the can.The other extreme is represented by the type of putty in which thepowder separates from the oil, settling in the bottom of the containerto a hard rock-like mass, with the separated oil on top. The powderoften sets up to such a hard rocklike mass that it is impossible toremove except with a sharp tool. Such putties, after standing for sometime, are valueless until they are completely reworked.

After being applied to the sash, either metal or wood, the putty mustremain in position and even withstand a reasonable amount of mechanicalshock before the putty has dried. This means that the body consistencymust possess a suificient degree of rigidity and have a high yieldvalue. It must also have a sufficient amount of resistance to plasticflow, so that the putty will remain in position after being applied tothe sash.

Putty powders that do not have the correct micron size distribution, orparticle size range often allow the oil or vehicle to separate from theputty after'ithas been applied to the sash. In extreme cases theoil willseparate in sufficient quantity to run down the sash.

The oil absorption is the amount of oil required to produce a putty ofthe correct working characteristics. It is usually defined as the amountof oil required for 100 pounds of powder. Oil absorptions may vary froma low of 8 or 9 pounds of oil per 100 pounds of powder up to a high of25 or 30 pounds of oil per 100 pounds of powder. In the production ofcommercial putties, oil absorption is highly important from the economicstandpoint. If a putty maker is using a powder having an oil absorptionof 11 and he then secures one with an oil absorption of 12, it meansthat he must use 20 pounds more of oil for every ton of powder. This isapproximately 3 to 3 /2 gallons of oil at a cost of approximately 3 to 6dollars extra on each ton of powder. It is, therefore, very importantthat oil absorption be controlled within comparatively narrow limits.

In addition to the use of putty powders having the required degree ofplastic quality that is typical of oolitic limestone, there should headded another method that was in common use in the past and is to someextent used today. This is the use of English chalk. By using moderatepercentages of English chalk or imported chalks in the range of usually20% to 30%, combined with a crystalline limestone powder, a putty havinga high degree of plastic flow and extraordinarily good qualities can beproduced.

Also, very acceptable putty powders can be produced by extremely finegrinding of crystalline limestones. If a portion of the powderconstituting the putty powder formula is ground to an average of 2 or 3microns, having a micron size distribution in which about 50% to 60% issmaller than 1 micron, then a very high degree of plasticity will, also,be developed. To produce the required and acceptable degree of plasticquality that is required for putties, caulking and glazing compounds,there are then fourwalternate formulations: (1) those based on ooliticlimestones; (2) those based on natural chalk plus crystallinelimestones; (3) those containing 20% to 40% of very fine groundcrystalline limestone plus coarser crystalline limestone powder; and (4)those containing relatively high percentages of heavy bodied oils in thevehicle portion.

All of these procedures have a common objection. They are costly ascompared to the powders that can be ground and produced from crystallinelimestones. The oolitic limestones, as previously mentioned, exist inonly one or two localities. For places remote from these points, thisinvolves high shipping cost. In the case of those depending upon the useof chalk, war or any other disturbing world condition can shut off thesource of supply. The present cost of importing is also excessive. Inthe case of. the very fine grinding, the cost of grinding the 20% to 40%portion of the powder is extremely high, resulting in a high cost forthe powder formula. Also, drying oils of the type describedare costlywhen used in any appreciable quantities in the vehicle portion of puttycompounds.

The greatest object to powders produced from crystalline limestones incomparison to any one of the four foregoing acceptable methods, is therather common lack of the proper degree of plasticity and plastic flowand the inclination to settle in the package after the product has beenstored.

It is therefore an. object of the present invention to provide a puttyexhibiting improved physical properties such as greater plasticity,better working qualities, improved wearing qualities, improved keepingqualities and less oil requirements while using as a powder basetherefor treated pulverized crystalline limestone rock.

Still another object is to provide an improved crystalline limestonepowder exhibiting improved physical properties suitable for use in themanufacture of putty 6 without requiring'mixture withspecial powders,special ized fine grinding or special oil vehicles.

A further object is to provide a method of treatingpulverizedcrystalline limestone to improve the physical properties of the powderto allow its use in the production of a putty of improved physicalproperties.

Still a further object is to provide a method of pro ducing aputtycapable of high efficiency in use, capable of maintaining highlydesirable properties during protracted use or storage and requiring lesscombined oil in its manufacture.

Another object is to provide a series of compounds which can be suitablycombined with pulverized limestone to improve the physical properties ofthe limestone and impart improved properties to putty when the treatedlimestone is incorporated in the manufacture thereof.

Other objects not specifically set forth will become apparent from thefollowing detailed description.

In the drawings:

Fig. l is a coordinate chart setting forth a curve which represents thevariation in adsorption of sodium thiosulfate with increasedconcentrations of sodium thiosulfate; and

Fig. 2 is a flow sheet setting forth a preferred method of forming thepowder of the present invention.

As stated above, limestone is capable of producing sufiiciently finepowders for use in the manufacture of putty. Normally, crystallinelimestone has not been found suitable for this purpose due to itsphysical properties which, when present in a putty composition, impartundesirable properties to the putty. Table I sets forth typical examplesof the size range of putty powders. In this table, three grades oflimestone powders are shown to illustrate the degrees of finenessavailable upon the pulverization of limestone. The nomenclature used inidentifying the grades (G, No. 3 SPP and C) is known in the art.

Of the: different grades shown in Table I, grade G is of the typeexhibiting the greatest percentage of fines. Generally speaking, puttypowder formulations made with such powders having a highpercentage ofparticles of a size less than five microns produce putties of remarkablylong fiow' and very satisfactory working and glazing characteristics;Such putties usually exhibit good keeping qualities. A' common practiceis to combine from 20%to 50% of fine powderwith 50% to of a coarserpowder. Such powder combinations normally produce satisfactory putties.An example of such a combination is a powder formed from 80% No. 3 SPPpowder and 20% G powder set forth in Table I. As stated above, however,when coarser powders produced from crystalline limestone areincorporated alone in a putty product, the resultant product is tooshort and mealy. However, by treating such powders in accordance withthe teachings of myinvention, the physical characteristics of thecoarsely pulverized limestone are so greatly altered as to allow itsincorporation into a putty product which in turn will exhibit highlyimproved physical properties.

I havefound that by treatment'of crystalline limestone powderswithsodiumthiosulfate, the'powders, when incorporated in the manufacture ofa putty, impart to the putty greatly improved physical properties. Suchputties exhibit a high degree of internal cohesion allowing mucheasier-application and manipulation in the hands of the glazier and alsoexhibit non-settling characteristics which allow almost indefinitestorage. For example, Table 11 sets forth samples of putties made fromfour difierent powders two of which were treated with sodium thiosulfatcaloneand two of which were treated with sodium thiosulfate and a rosin,namely, W-2 resin. Also in- 1 oolitic limestone. Powders .G and No.3.SlP were-proe duced from crystalline limestone.

The reduction of oilabsorption of the powders that were treated withsodium thiosulfate or with sodium thiosulfate and resin showed that thepercentageof-oil required toproduce a product of theproper putty-likeconsistency was reduced from 5%; to 25%. The average reduction wasslightly over The reduction in the amount of oil required is alsoprobably a function. of thesurface area of the powder. The coarserpowders gave less reduction, running from 5% to 12%. The finer powdersgave a high reduction in oil absorption, running from 10% to It wasreasoned that this difierence was probably due to surface area.

Table II Oil Ab Powder Surface Treatment Vehicle sorp- Standing OilSepa- Condition After Standing a tion, Time ration Lbs.

L None Raw linseed oil. 14. 94 1 year..- Yes..." Lumpy-bottom 5 dry,mealy-hard. L dgyiNarisionfiH o, 0.2% .....do 11. 97 do Nona...Semipkistie. Easily reworked. Fair condition.

- I'ES Y1.

Difference... 2. 97 7 None. Raw linseed oil.-. 11.03 -do...-. Yes- Firm,hard, solid, poor condition. 0.32% NmSzOsjHzO ..dlo 10. 77 do Slight...Seiniplastic. Fair condition.

Difierence... 1.15 V v G.. None Raw linseed oil.-. 14.18 do Yes.Progressive stiifening to bottom. Poor condition. '6 0.47% NHQSQOL5HSO,-.do 10. 87 .do.. Slight... No settling. About as when put in can.

0.30% W-2 resin. I

Difierence... 3. 31

No. 3 SP1..- None Raw linseed oil. 12. 61 -.do. Yes.-.- Dry and mealythroughout. Poor condition. No. 3 SPP 0.01% NMSQOIL5H2O do 11. 82 do..Slight... Soft and plastic. Fair condition.

Difierence... I 0.79

the powder as compared to the treated powder. Using these figures, thesaving in oil would amount to approximately 2 gallons and, at itspresent market price, this would amount to a savings of from 2 to 4dollars per ton of putty. The feature of reduced oil requirements isfurther borne out by the results obtainedin connection with the Gpowder. Here there is a savings of roughly 9 gallonswhich would amountto a dollar savings of from 9 dollars to 27 dollars per ton of product.

Another important feature which should be noticed from the results inTable II is the condition of the putty 0 following storage for one year.In every case the untreated powders mixed with raw linseed oil to puttyconsistency and stored in a 10 pound can for one year became firm andhard. These products showed considerable oil separation and wherein sucha poorcondition that it would be necessary to rework them before theycouldbe applied to a sash or building. On the other hand, all of thetreated powders resulted in a-putty showing a much better condition atthe end-of one year. None of them were hard and there was very littleoil separation. Most ofthem could be used with a moderate amount ofreworking just as they came from the storage can. The same degree ofimprovement is effected with powders produced from either crystalline oroolitic stone. Powders L and C were-produced from Oil absorption variesfrom 0.79- pounds of 45 In orderto provide a theoretical. basis by whichto guide the'research work on Na S O and resin treatment of puttypowders,;it was first decided to investigate the 200 mesh 0.0029 in.opening do 86.8730 325 mesh ,0.0017,in. opening do 72.7200

Micron'size distribution; Percent Plus 25 microns". 38.3 10 to 25microns.., 17.0 5 to-IO micron V 15.1 V l-to 5 microns. 28.4 Minus 1micron 1.2

Table IV Concentration NazSzOa Concern Quantity Sol. Before Adsorptiontratiou adsorbed z NBJSZOZ 113720061115. 7,; "fist Sgl'Attor 1t-((d37)O. SOID- OW er- Gms. Gms. tlon Gms. 3 533 NszSzOz NaiSzOa Gms. NfiQSiOSpe Gm in 250 cc. Per cc. NaiSiOa Adsorbed,

in 250 cc otal The results of tIeating'ZOO grams of the powder with 'Nas o. solutions of constantly increasing strength showed an increasingadsorption of the Na S O as a function of solution strength. Column 10plasticity; It produces a more dense bodywith a high and more desirabledegree of plasticity and the adhesion value is also considerablyimproved. The critical range x of the rosin treatment is between 0.5%and 5.0%. Bem tween these limits the maximum effects on the physical ofTable IV shows the sodium thiosulfate adsorbed per Pfepertiss 0f the P ymade from the heated Pelt/tier is gram of calcium carbonate at thevarious solution conproduced- This then would form the c1titi'ehl rangeof centrations. The solution which contained 0.00008208 the resin q rWhether the powder was treated with gram of sodium thiosulfate per cubiccentimeter resulted l'esih y a combination of f z z s and rest!!- in anadsorption of 00000096 gram of sodium thiosulfate he are tyifo methodswhich the P e y per gram of Thecolumn treated. One is to introduce thereagents dlrectly into the mill onto the rock as it is pulverized. Inthe case of x treating with both of these reagents the two reagents mwould be metered in separately, the sodium thiosulfate shows aconstantly increasing value in relationship to in a water solution andthe resin in a. solvent solution; the constantly increasing strength ofsodium thiosulfate There 15 110 dahgel: 0f hazard from P h the solutionThese results are plotted on the accompanysolvent as the calciumcarbonate dust would 1nh1b1t or ing drawing in Fig. 1 wherein acoordinate chart and a stop any m Propagation t treating liquids arecurve is drawn which conforms very closely the Freundi i' i Onto thefeels y eterlng pumps or preferably lich adsorption isotherm formula. NaS O solutions of J inside the 111111 so t lhtlmate thorough higherstrength than No. 10 resulted in a decreased -ad tact With the reagentsis formed With t Particles that sorpt-ion. The strength of 0.00657 gramNa S O per cc. a prodflced durmg e-pr of srgave approximately thehighest degree f adsorption ring to F1g. 2 of the drawings, there isdepicted a schemat- Table V below shows the flf t f treating powders icarrangement for treating the limestone in accordance with differentlevels of sodium thiosulfate. In this ex- With the teachings 0f thePresent ihVehtiOh to secure the perirnent the powders were treated withsolutions of such desired product The e n from tank 1 is passed a.strength as to give the corresponding adsorption of through a line 3 inWhich is interposed a p p 4 and Na S 0 per gram of powder that wouldcorrespond with how meter to a feed Valve The feed Valve 6 is thosetaken f h adsorption i h experiments located in the conduit 7 whichcarries the crushed rock Table V also shows that there was a reductionin oil p to 2 and 3 inches in diameter from the 1 ill t adsorption from12.34 to 10.91 when only 0.005% of the mill i 8 is preferably a ringroll or mm N s o was d, Thi i only t fl of a u d mill suitable forreceiving relativey large pieces of limeper ton of powder. The lowestoil absorption was given stone and discharging fineiy ground material,at a high by 0.025% of Na S O which is equivalent to 0.5 pound rate ofproduction such as, for example, 5 to 7 tons per of sodium thiosulfateper ton of powder. 0n the basis oldillarily the limestone isshhieetedte'the grindof these ex eriments as well as practicalexperiments in s action y a Short time, not over about 1 t 3 theapplication of sodium thiosulfate in the processes of minutes and-in minstances considerably 1ess t a grinding and mixing the critical limitshould be set at a min te. The treated pulverized rock is withdrawn lowof .0001% and a high of 5.0% based on the weight through the pipe 9 bymeans of a blower 11' andpasses of the powder. The greatest effect willfall within this to a dust collector 12. 'The' dustis collectedby' thecolbracket and in fact before reaching 5.0% the oil adsorplector 12 andthe pulverized material passes to a bin 13 tion isotherm will havedropped. That is, the quantity while the air carrier is returned to. themill through pipe or Na S O adsorbed per gramwill have decreased and 14.Treatment apparatus of the type schematically the oil adsorption willthenbegin to rise. shown can be suitably used in supplying a solution ofT able V Grns. Total Total Putty Exp. NasSzOs Gms. NfizSzQa PercentTotal Vol. of

No. Adsorbed Powder Reqd, NarSiOs NasSzOs-l- 501., 00. 011 Abs.

Per Grn. Used, Gms. 5H20 ofPowder Gms.

P7-22-05. 0.00005 4,536 0. 2208 0.005 0.356 300 10.91 P72266 4,536 0.6804 0.015 1. 068 300 10.91 P72267 4,530 1.1340 0. 025 1.780 300 10.76P7-2268 None 4,536 None None None None 12. 34 P7-22-69 None 4,536 NoneNone None None 1 11.55

i 0.3% W-2 resin in 200 cc. solvent.

Table V shows the effect on the reduction of oil absodium thiosulfateand a solvent solution of resin to the sorption by treating the powderwith 0.3% of W-Z resin mill 8 during grinding of the limestone rock. Thedifdissolved in 200 cc. of solvent. In this case the solvent ference inthe instance where more than one reagent is was naphtha. Resin, whetherit be the W-Z or any other used is that there would have to besufficient solution grade of normal wood resin, has the efiect ofreducing the tanks and metering pumps provided to introduce each oilabsorption to some extent but its most pronounced reagent separately.efiect is in its modification of the plastic performance of Carefulcontrol must be maintained over the concenthe powder. A very smallpercentage of resin introduced tration of the sodium thiosulfatesolution, as shown by the onto the surface of the powder considerablyincreases absorption efiects in Table II that occur with a change in thepl y and also the suspension qualities. When the solution concentration.The solution concentration this treatment is combined with the sodiumthiosulfate would normally contain from 0.00008 to 0.007 gram of surfacetreatment there is a very pronounced improvesodium thiosulfate per cc.Expressed in gallons this ment in the physical qualities of the powder.I}: prould be as follows; duces powder with a very low oil absorption, tereby saving from 5% to 25% of the oil normally required by @githlosulfate the untreated powder. There is a very definite improvei f 1ment in the keeping qualities of the powders as shown in ga OHS 0 soutlon Table II. Also the putty has a much higher degree of The resin isdissolved in zylol, benzine or naphtha or 11 any other suitable solventoncombination thereofiin the general proportion of to 25 grams of theresin to 100 cc. of solvent. As an example, a solution containing 104.25lbs. resin to 50 gallons solvent contains approximately 25 grams ofresin per 100 cc. of solvent. These solutions are then metered onto 'therock at a rate that will'introduce the quantity of Na S O or resindesired within the critical limits.

Another method of producing the product is to'first grind the powder inthe mill and then introduce the required amount of the sodiumthiosulfate solution into a known amount of'the powder in a mixer. Atthe same time the solvent solution of resin is introduced into themixture and the mixing process'is then continued until the two solutionshave thoroughly coated the surface of the particles. In experimentalwork conducted on this product, it has been found that thesodium"thiosulfate solution is best incorporated in the proportion of300 cc. of solution to 10 pounds of powder and the resin solution in theproportion of 100 cc. of, solution to 10 pounds of powder. These twoproportions, give extraordinarily good coverage and eifectivedistribution of the surface treating reagents over the surface of thepowders. g g The powder is then dried subsequent to the mixing procedureto remove the excess solvent and water. The mixing procedure produces aproduct having the lowest oil absorption and the highest degree ofplasticity.

Lhave found that by treatment of limestone with st dium thiosulfate orsodium thiosulfate and rosin, highly modified powders can be producedand that there is a synergistic action when the combined reagents areused, i.'e., the one will enhance or greatly increase the properties ofthe other. This is an unusual phenomenon and isone not frequentlyencountered in the application of treating reagents of various kinds inthe industrial arts.

T 'his application is a division of my copending applicationQSerial No.575,861, filed April's, 1956. 7

Obviously many modifications and variations of the invention ashereinbefore set forth may be made without departing from the spirit andscope thereof, and therefore only ,such limitations should be imposed asare indicated in :the appended claims. Iclaimz, 1. A putty compositionwhich exhibits a high degree of plastic flow, cohesion and adhesion withminimized combined oil vehicle requirements, said composition consistingessentially of a treated pulverized limestone powder and a drying oilvehicle in proportions yielding a putty-likeconsistency, the powderparticles being provided with surface coatings of sodium thiosulfateapplied to the particle surfaces prior to putty composition formulation,the surface coatings ranging from 0.000l% to 5.0% by weight of thepowder.

2. A putty composition which exhibits a high degree of plastic flow,cohesion and adhesion with minimized combined oil vehicle requirements,said composition consist ing essentially of a treated pulverizedlimestone powder and a drying oil vehicle in proportions yielding aputty like consistency, the powder particles being provided with surfacecoatings of sodium thiosulfate applied to the particle surfaces prior toputty composition formulation, the surface coatings ranging from 0.0001%to 5.0% by weight of the powder, the drying oilvehicle being formed atleast substantially from a straight putty oil with any heavy-bodied andhighly viscous drying oil content thereof being no greater than 20%.

3. A putty composition which exhibits a high degree of plastic flow,cohesion and adhesion with minimized combined oil vehicle requirements,said composition consisting essentially of a treated pulverizedlimestone powder and a drying oil vehicle in proportions yielding aputtylike consistency, the powder particles being provided with surfacecoatings of sodium thiosulfate applied to the particle surfaces prior toputty composition formulation, the surface coatings ranging from 0.000l%to 5.0% by weight of the powder, the treated powder providingfor areduction in drying oil vehicle absorption of from about 5% to 25% byweight of the vehicle.

4. The method of preparing a putty composition, said method comprisingpulverizing limestone rock under particle-size reduction conditions,metering onto said rock during pulverization thereof quantities ofsodium thiosulfate ranging from 0.0001'% to 5.0% by Weight of thelimestone, the sodium thiosulfate as metered onto the rock being inliquidized form, and combining the treated powder with a drying oilvehicle in proportions yielding a putty-like consistency.

References Cited in the file of this patent v UNITED STATES PATENTS

1. A PUTTY COMPOSITION WHICH EXHIBITS A HIGH DEGREE OF PLASTIC FLOW,COHESION AND ADHESION WITH MINIMIZED, COMBINED OIL VEHICLE REQUIREMENTS,SAID COMPOSITION CONSISTING ESSENTIALLY OF A TREATED PULVERIZEDLIMESTONE POWDER AND A DRYING OIL VEHICLE IN PROPORTIONS YIELDING APUTTY-LIKE CONSISTENCY, THE POWDER PARTICLES BEING PROVIDED WITH SURFACECOATINGS OF SODIUM THIOSULFATE APPLIED TO THE PARTICLE SURFACE PRIOR TOPUTTY COMPOSITION FORMULATION, THE SURFACE COATINGS RANGING FROM 3.0001%TO 5.0% BY WEIGH OF THE POWDER.